"""
See the file DB.drawio for the design of the database. It can be opened in the internet browser with the website:
https://app.diagrams.net

For more information about the implementation, see the part to Models in the documentation of Flask-SQLAlchemy:
https://flask-sqlalchemy.palletsprojects.com/en/2.x/models/
"""

# Imports
from flask import flash, has_request_context
from flask_security.models.fsqla_v2 import FsRoleMixin, FsUserMixin

# Importing the database instance
from advlabdb import db
from advlabdb.configUtils import getConfig


class Student(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    student_number = db.Column(db.Integer, db.CheckConstraint("student_number > -1"), nullable=False, unique=True)
    first_name = db.Column(db.String(100), nullable=False)
    last_name = db.Column(db.String(100), nullable=False)
    uni_email = db.Column(db.String(200), nullable=False, unique=True)
    contact_email = db.Column(db.String(200), unique=True)
    bachelor_thesis = db.Column(db.String, nullable=True)
    bachelor_thesis_work_group = db.Column(db.String, nullable=True)
    note = db.Column(db.Text, nullable=True)
    part_students = db.relationship("PartStudent", backref="student", lazy=True)

    def repr(self):
        return f"{self.first_name} {self.last_name}"

    def __repr__(self):
        return f"<STD {self.repr()}>"


class PartStudent(db.Model):
    # A student doing a specific part
    id = db.Column(db.Integer, primary_key=True)
    final_part_mark = db.Column(
        db.Integer,
        db.CheckConstraint("final_part_mark > -1"),
        db.CheckConstraint("final_part_mark < 16"),
        nullable=True,
    )
    student_id = db.Column(db.Integer, db.ForeignKey("student.id"), nullable=False)
    part_id = db.Column(db.Integer, db.ForeignKey("part.id"), nullable=False)
    group_id = db.Column(db.Integer, db.ForeignKey("group.id"), nullable=True)
    experiment_marks = db.relationship("ExperimentMark", backref="part_student", lazy=True)

    __table_args__ = (
        db.UniqueConstraint(student_id, part_id),
        db.UniqueConstraint(student_id, group_id),
    )

    def repr(self):
        return f"{self.student.repr()} {self.part.repr()}"

    def __repr__(self):
        return f"<PARTSTD {self.repr()}>"


class Group(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    number = db.Column(db.Integer, db.CheckConstraint("number > 0"), nullable=False)
    part_id = db.Column(db.Integer, db.ForeignKey("part.id"), nullable=False)
    part_students = db.relationship("PartStudent", backref="group", lazy=True)
    group_experiments = db.relationship("GroupExperiment", backref="group", lazy=True)

    __table_args__ = (db.UniqueConstraint(number, part_id),)

    def customInit(part, partStudents):
        orderedPartGroups = Group.query.filter(Group.part == part).order_by(Group.number)
        lastTakenGroupNumber = orderedPartGroups[-1].number if orderedPartGroups.count() > 0 else 0

        return Group(
            number=lastTakenGroupNumber + 1,
            part_students=partStudents,
            part=part,
        )

    def repr(self):
        return f"{self.number} {self.part.repr()}"

    def __repr__(self):
        return f"<GR {self.repr()}>"


class GroupExperiment(db.Model):
    # An experiment specified to a group
    id = db.Column(db.Integer, primary_key=True)
    semester_experiment_id = db.Column(db.Integer, db.ForeignKey("semester_experiment.id"), nullable=False)
    group_id = db.Column(db.Integer, db.ForeignKey("group.id"), nullable=False)
    appointments = db.relationship("Appointment", backref="group_experiment", lazy=True)
    experiment_marks = db.relationship("ExperimentMark", backref="group_experiment", lazy=True)

    __table_args__ = (db.UniqueConstraint(semester_experiment_id, group_id),)

    def customInit(semester_experiment, group):
        for partStudent in group.part_students:
            student = partStudent.student
            for partStudent in student.part_students:
                for experimentMark in partStudent.experiment_marks:
                    if experimentMark.group_experiment.semester_experiment.experiment == semester_experiment.experiment:
                        raise Exception(
                            f"{student} has already done {semester_experiment.experiment} in {partStudent.part} and had {experimentMark}!"
                        )

        return GroupExperiment(semester_experiment=semester_experiment, group=group)

    def repr(self):
        return f"SemExp {self.semester_experiment.repr()}; Gr {self.group.repr()}"

    def __repr__(self):
        return f"<GREXP {self.repr()}>"


class Experiment(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    label = db.Column(db.String(20), nullable=False, unique=True)
    title = db.Column(db.String(200), nullable=False)
    description = db.Column(db.Text, nullable=True)
    wiki_link = db.Column(db.String(200), nullable=True)
    room = db.Column(db.String(100), nullable=False)
    building = db.Column(db.String(100), nullable=False)
    responsibility = db.Column(db.String(200), nullable=True)
    duration_in_days = db.Column(db.Integer, db.CheckConstraint("duration_in_days > -1"), nullable=False)
    active = db.Column(db.Boolean, nullable=False, default=True)
    oral_weighting = db.Column(db.Float, nullable=False)
    protocol_weighting = db.Column(db.Float, nullable=False)
    final_weighting = db.Column(db.Float, nullable=False)
    semester_experiments = db.relationship("SemesterExperiment", backref="experiment", lazy=True)

    def repr(self):
        return f"{self.label}"

    def __repr__(self):
        return f"<EXP {self.repr()}>"


# Helper table for the many to many relationship between Assistant and SemesterExperiment
experiment_assistant = db.Table(
    "experiment_assistant",
    db.Column("semester_experiment_id", db.Integer, db.ForeignKey("semester_experiment.id"), primary_key=True),
    db.Column("assistant_id", db.Integer, db.ForeignKey("assistant.id"), primary_key=True),
)


class SemesterExperiment(db.Model):
    # An experiment in a specific semester
    id = db.Column(db.Integer, primary_key=True)
    experiment_id = db.Column(db.Integer, db.ForeignKey("experiment.id"), nullable=False)
    semester_id = db.Column(db.Integer, db.ForeignKey("semester.id"), nullable=False)
    assistants = db.relationship(
        "Assistant", secondary=experiment_assistant, lazy=True, backref=db.backref("semester_experiments", lazy=True)
    )
    group_experiments = db.relationship("GroupExperiment", backref="semester_experiment", lazy=True)

    __table_args__ = (db.UniqueConstraint(experiment_id, semester_id),)

    def repr(self):
        return f"{self.experiment.repr()} {self.semester.repr()}"

    def __repr__(self):
        return f"<SEMEXP {self.repr()}>"


class Assistant(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    first_name = db.Column(db.String(100), nullable=False)
    last_name = db.Column(db.String(100), nullable=False)
    phone_number = db.Column(db.String(50), nullable=True)
    mobile_phone_number = db.Column(db.String(50), nullable=True)
    room = db.Column(db.String(100), nullable=True)
    building = db.Column(db.String(100), nullable=True)
    user_id = db.Column(db.Integer, db.ForeignKey("user.id"), nullable=False, unique=True)
    appointments = db.relationship("Appointment", backref="assistant", lazy=True)
    experiment_marks = db.relationship("ExperimentMark", backref="assistant", lazy=True)

    def repr(self):
        return f"{self.first_name} {self.last_name}"

    def __repr__(self):
        return f"<ASST: {self.repr()}>"


class Appointment(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    date = db.Column(db.Date, nullable=False)  # To be specified with the python package "datetime"
    special = db.Column(db.Boolean, nullable=False)  # In the break or not
    group_experiment_id = db.Column(db.Integer, db.ForeignKey("group_experiment.id"), nullable=False)
    assistant_id = db.Column(db.Integer, db.ForeignKey("assistant.id"), nullable=False)

    def checkAndGetAssistant(assistant, groupExperiment):
        semesterExperiment = groupExperiment.semester_experiment
        semesterExperimentAssistants = semesterExperiment.assistants

        if not semesterExperimentAssistants:
            raise Exception(f"{semesterExperiment} has no assistants yet!")

        if assistant:
            if assistant not in semesterExperimentAssistants:
                raise Exception(f"{assistant} not responsible for {semesterExperiment}!")
        else:
            if len(semesterExperimentAssistants) == 1:
                assistant = semesterExperimentAssistants[0]
            else:
                raise Exception(
                    f"Experiment {semesterExperiment} has more than one assistant. You have to assign one of these assistants: {semesterExperimentAssistants}"
                )

        return assistant

    def customInit(date, special, assistant, groupExperiment):
        assistant = Appointment.checkAndGetAssistant(assistant, groupExperiment)

        return Appointment(
            date=date,
            special=special,
            group_experiment=groupExperiment,
            assistant=assistant,
        )

    def customUpdate(self, date, special, assistant, groupExperiment):
        assistant = Appointment.checkAndGetAssistant(assistant, groupExperiment)

        self.date = date
        self.special = special
        self.assistant = assistant
        self.group_experiment = groupExperiment

    def repr(self):
        return f"{self.date} {self.group_experiment.repr()}"

    def __repr__(self):
        return f"<APPT {self.repr()}>"


class Part(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    label = db.Column(db.String(100), nullable=False)  # A/1, A/2, B/1, B/2
    semester_id = db.Column(db.Integer, db.ForeignKey("semester.id"), nullable=False)
    part_students = db.relationship("PartStudent", backref="part", lazy=True)
    groups = db.relationship("Group", backref="part", lazy=True)

    __table_args__ = (db.UniqueConstraint(label, semester_id),)

    def repr(self):
        return f"{self.label} {self.semester.repr()}"

    def __repr__(self):
        return f"<PART {self.repr()}>"


class Semester(db.Model):
    id = db.Column(db.Integer, primary_key=True)
    label = db.Column(db.String(100), nullable=False, unique=True)  # WS2122 for example
    parts = db.relationship("Part", backref="semester", lazy=True)
    semester_experiments = db.relationship("SemesterExperiment", backref="semester", lazy=True)
    active_users = db.relationship("User", backref="active_semester", lazy=True)

    def repr(self):
        return f"{self.label}"

    def __repr__(self):
        return f"<SEM {self.repr()}>"

    def transferPartsFrom(self, oldSemester):
        if oldSemester:
            partLabels = [part.label for part in oldSemester.parts]
        else:
            partLabels = getConfig("defaultPartLabels")

        for partLabel in partLabels:
            db.session.add(Part(label=partLabel, semester=self))


class ExperimentMark(db.Model):
    # A mark for a student after a specific experiment
    id = db.Column(db.Integer, primary_key=True)
    oral_mark = db.Column(
        db.Integer, db.CheckConstraint("oral_mark > -1"), db.CheckConstraint("oral_mark < 16"), nullable=True
    )
    protocol_mark = db.Column(
        db.Integer, db.CheckConstraint("protocol_mark > -1"), db.CheckConstraint("protocol_mark < 16"), nullable=True
    )
    part_student_id = db.Column(db.Integer, db.ForeignKey("part_student.id"), nullable=False)
    group_experiment_id = db.Column(db.Integer, db.ForeignKey("group_experiment.id"), nullable=False)
    assistant_id = db.Column(
        db.Integer, db.ForeignKey("assistant.id"), nullable=True
    )  # The assistant who gave the mark

    __table_args__ = (db.UniqueConstraint(part_student_id, group_experiment_id),)

    def repr(self):
        return f"Oral {self.oral_mark}; Prot {self.protocol_mark}"

    def __repr__(self):
        return f"<EXPMARL {self.repr()}>"


class User(db.Model, FsUserMixin):
    assistant = db.relationship("Assistant", backref="user", lazy=True, uselist=False)
    active_semester_id = db.Column(db.Integer, db.ForeignKey("semester.id"), nullable=True)

    def repr(self):
        return f"{self.email}"

    def __repr__(self):
        return f"<USR {self.repr()}>"


class Role(db.Model, FsRoleMixin):
    def repr(self):
        return f"{self.name}"

    def __repr__(self):
        return f"<ROLE {self.repr()}>"